Absorbency is an important attribute in consumer paper products such as bathroom tissue, towels, and napkins. This attribute is strongly influenced by the sheet structure of a paper product. Further, the types of fiber employed in the sheet are important factors in determining the absorbency and strength of products made from such fibers.
It is well known in the art that cellulosic fibers vary in their properties such as fiber length, fiber cell wall rigidity, fiber coarseness, lumen size, etc. Short fibers, including fines, in some instances may be considered less desirable fibers in most fiber slurries. In the past, such fines comprised short portions of cellulosic material which do not appreciably contribute to softness. Further, such fines may be too small to remain on a wire former in the papermaking process, and often fall through the wire mesh of the wire former with the water when a paper slurry is applied on the twin wire former in the early stages of paper manufacture. Thus, such fines may be simply washed from the system, and may not contribute in any meaningful way to the final paper product. Further, these fines may comprise cellulosic particles that undesirably absorb a large amount of the treatment chemicals that are used in the headbox at the early stages of slurry formation. In fact, such fines may undesirably absorb process chemicals which otherwise could be applied to the longer fibers which in fact do become part of a paper product. In this way, fines may waste processing chemicals by carrying such chemicals out of the processing system.
Further, a process that is able to employ and retain short fibers and long fibers in a way that provides a paper product with improved absorbency while also providing desirable strength and softness, would be advantageous.
It has been discovered that short fibers at a particular level within the furnish, with particular rigidity and lumen diameter features, provide desirable absorbency attributes, without sacrificing other desirable strength and softness attributes. Through the selection of the appropriate level, cell wall rigidity, thickness, and shape of the shorter cellulose fibers, an improved paper structure is provided having improved water channeling and absorption effects.